Mineral oil composition and improving agent therefor



Patented Apr. 10,- 1945 UNITED STATES PATENT oer-ice MINERAL OILCOMPOSITION AND MPROV- ING AGENT THEREFOR Darwin E. Badertscher, RobertB. Williams, and Henry G. Berger, Woodbury, N. J assignors toSocony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporationof New York No Drawing.

1939, Serial No.

Original application October 5, 298,052, now Patent No.

2,279,218, dated April '7, 1942. Divided and this application January 8,1942, Serial No. 426,002

6 Claims.

This application, which is a division of our copending applicationSerial No. 298,052, filed October 5, 1939, now Patent No. 2,279,218,issued April 7, 1942, relates to viscous mineral oil compositions of thelubricant and dielectric types which have been improvedin one or more oftheir various properties by having admixed therewith a minor proportionof mineral oilimproving agent. More specifically, the invention isconcerned with the production of a novel class of mineral oil-improvingagent and with the production of improved mineral oil compositions ofthe viscous type containing one or more of these novel improving agents.

It is well known to those familiar with the art that the deterioratingeffect of oxidation and continued use upon a mineral oil fractionmanifests itself in various ways, depending upon the source of theoil-that'is, the crude from which it is derived-the refining treatmentto which the oil has been subjected, and the particular conditions underwhich the oil is subjected to oxidation. Motor oils, for example,especially those refined by certain solvent-extraction methods, tend tooxidize when subjected to high temperatures and form' products that arecorrosive to metal bearings. This corrosive action maybe severe withcertain bearing metals such as the hard metal alloys of thecadmium-silver and copper-lead types, and the class of improving agentscontemplated herein are particularly useful as inhibitors of oxidationand the attending bearing-corrosion in oils of this character.

The oil-improving agents contemplated herein -also find valuableapplication in the field of motor-lubrication as inhibitors of theformation of materials which lead, on accumulation, to the sticking ofpistonrings and the filling of the slots in oil rings.

Certain of these improving agents are also useful in oils which havebeen refined for turbine or transformer use, particularly ,those whichhave been highly refined to retard the deterioration of such oils andthe attending development of acid or sludge which takes place under theconditions of use.

Although the general class of compounds or reaction productscontemplated herein finds application principally in the field ofoxidation-inhibitors, and particularly as improving agents for internalcombustion engine lubricants, it is to be understood that theseimproving agents may efiect improvement in other respects or properties,such as load-carrying capacity, and, as indicated above, certain membersof the class, at least, are effective acid-inhibitors for highly refinedturbine and transformer oils. In this same connection our inventioncontemplates, as an especially preferred group or type of improvingagents falling within the general class, compounds or reaction productswhich are multifunctional in that they possess in addition to theinhibiting properties mentioned above, the property of improving thepour point of the oil to which they are added.

The oil-improving agents contemplated herein have as theircharacterizing constituent a re-' action product obtained by reacting aphosphorus pentahalide with an aromatic hydroxycarboxylic 10 acid whichwe may represent by the general formulae:

R CO OH and R OH R COOH the group consisting of hydrogen, alkyl, aryl,aralkyl, and alkaryl radicals. The foregoing reaction may be representedby the following equation, wherein the ortho-hydroxy acid is used forpurposes of illustration:

0 L-on 0 40 PCls 21101 or on o as I/Cl wherein the Rsrepresent radicalsselected from.

general formula:

H HOH coon on:- cH= H These two acids, salicyclic acid and thymotinicacid, will be used herein to illustrate the manner of synthesizing thevarious oil-improving agents and to demonstrate their efiectiveness inmineral oil compositions.

EXAMPLE SYNTHESIS or PCLs-AROMATIC ORTHO-HYDROXY CARBOXYLIC AcrnREACTION PRODUCTS (a) Pc'lo-salicyclic acid reaction product One mol ofsalicyclic acid and one mol of phosphorus pentachlorlde were mixedtogether in a large flask fitted with a. stirrer and reflux condenser.The mixture was heated on a water bath to a temperature not exceeding 80F. and stirred until H01 evolution ceased. Hydrogen chloride evolutioncommenced" when the reactants were mixed and became quite vigorous atthe elevated more of these improving agents to provide the lubricantfilm.

To demonstrate the effectiveness of the improving agents contemplatedherein as inhibitors of corrosive action of the type above referred to,samples of a motor lubricating oil and of an oil blend containing arepresentative improving agent, salicyclic-Pclo product, were tested bysuspending a G-gram section of a hard metal alloy bearing in a 30-gramsample of the oil or blend and heating it to about 175 C. for 22 hourswhile bubbling a stream of air against the surface of the bearing. Theweight loss in milligrams of the bearing section is interpreted as ameasure of the corrosiveness of the oil. The alloy bearing section inboth cases was from a cadmium-silver bearing, and the oil was acommercial S. A. E. 20 solvent-refined motor oil. Results of this testare given below in Table I.

To further demonstrate the effectiveness of the improving agentscontemplated herein as inhibitors of corrosive action of the typereferred to above, samples of a motor lubricating oil and ofan oil blendcontaining the same representa- -rtive improving agent, Salicylic-PO15product,"

were subjected to the Lauson engine test. These tests were made with aconventional single-cylinder, 4-cycle, liquid-cooled Lauson engine whichtemperature. The resulting product was a lightcolored liquid which willbe hereinafter referred to as the Salicyclic-PCh product."

(1)) Pcls-thamotinic acid reaction product Following the same proceduredescribed above, equal molecular proportions of thymotinic acid andphosphorus pentachloride were reacted together to yield a brown liquidproduct which will be hereinafter referred to 'as Thymotinic-PClrproduct.

(c) PCls-beta-hydroxy-aZphanaphthoic acid reaction product Fifteen gramsof beta-hydrqxy-alpha-naphthoic acid and 22%. grams of PCls were stirredtogether without external application of heat. A spontaneous reactionoccurred, accompanied by a temperature rise from 28 C. to 42 C., forminga. dark oil. This was taken up in 100 c. c. of petroleum ether and 10 c.c. of benzene and n1- tered. The solvents were partially removed in a.vacuum dessicator, yielding a white crystalline in, a method forlubricating alloy bearings which involves the use of a lubricantcontaining one or had been equipped with an electrically heated sump, anoil pump, and a reflux condenser attached to the cooling jacket. Duringthe test operation the temperature of the oil going into the engine fromthe sump was maintainedat 300 F., and it was circulated at the rate of40 gallons per hour. The temperature of the cooling jacket was about 212F., and the engine was operated at a speed of approximately 1810 R. P.M., the power output at this speed (about 0.5 H. P.) being absorbed byan A. C. induction motor coupled directly to the crank shaft of theengine. The oil, or oil blend, under' test was inspected at the end of12 hours, and again at the end of 24 hours, and finally at the end of 36hours when the test run was completed. At each inspection (12, 24, and36 hours) the oil, or oil blend, was tested for acidity orneutralization number (N. N.) and Kinematic viscosity (K. V.) at 210 F.At the 24 hour and 36 hour inspections, the oil, or oil blend, wastested still further for the amount of A. S. T. M. naphtha insolubles.The mineral oil stock used in these tests was an S. A. E. 10solvent-refined motor oil. The results obtained are listed in Table 11below.

In addition to the foregoing motor oil tests, a typical improving agentcontemplated herein was blended with a motor oil andsubiected to anaccelerated engine operation test to evaluate its ability to preventring-sticking, etc;,in engine operation. The engine employed in the testwas a standard C. F. R. knock test" engine and the test involvedoperating the engine firstwith the oil and then with the oil blend at anapproximate speed of 1,200 R. P. M. with the throttle set just belowdetonation, using a compression ratio of 7:1

and a jacket temperature of 400 F.

At the end of 28-hour-test runs, the following inspections were made:

The results obtained are low, where-oi1 A" is the motor oil blank andoil B" is the same oil containing 1.0% of the Salicyclic-PO15 product.

TABLEIII Degrees stuck 23: 5 Used oils on deposits a 1 2 a 4 5 a v4 .5N.-N.

A ussoacoacossoasovo 7o 90 13.9 30.02 2.2 B 0000010205 1.2 2ii.34 l.6

The ability of the improving agents contemplated herein to increasepacity of lubricants has been demonstrated'with the Salicylic-PO15product." A typical gear oil which failed in the Almen test at a load of3,000 pounds passed the same test at a load of 30,000+ pounds whenblended with 5.0% of the Salicylic-PCl5 product."

The amount 01' improving agents which may be used in the oil will varymore or les -with the oil and the conditions of use, but in general thedesired improvement can be eflected with amounts ranging from about0.01% to about 10%.

It is to be understood that while we have herein described certainpreferred procedures for synthesizingimproving agents of the typecontemplated by this invention and have designated certain illustrativereactants which may be employed,

the invention is not confined to the specific detailed proceduraloperations or reactants delist din Table III bethe load-carryingcamixture therewith a minor proportion. of a.reaction product obtainedby reacting phosphorus pentachloride with salicylic acid, said mineraloil composition being free of sulfur. 5 4. An improved mineral oilcomposition co prising a viscous mineral oil fraction and in admixturetherewith a minor proportion of a reaction product obtained by reactingphosphorus pentachloride with thymotinic acid, said mineral 10 oilcomposition being free of sulfur.

5. An improved mineral oil composition comprising a viscous mineral oilfraction and in admixture therewith a minor proportion 01' a reactionproduct obtained by reacting phosphorus group having the generalformulae:

a on R coon R on in which the R' represent radicals selected from thegroup consisting of: hydrogen, alkyl, aryl, aralkyl. and alkarylradicals, said mineral oil composition being free of sulfur. p

6. The method of lubricating relatively moving metallic bearing surfaceshaving the corrosionsusceptibility of hard metal alloys of thecadmium-silver type which comprises maintaining between the bearingsurfaces a lubricant film having as a primary lubricating constituentthe combination of a major portion of a mineral oil normally corrosiveto alloys of the cadmium-silver type and a minor proportion of areaction product obtained by reacting phosphorus pentachloride with a.compound selected from the group having the general formulae:

scribed but includes within it scope whatever changes fairly come withinthe spirit oi'the appended claims.

We claim: 'g 1. An improved mineral oil composition comprising a viscousmineraloll fraction and in admixture therewith a minor proportion oi areaction product obtained by reacting a phosphoru pentahalidewith anaromatic hydroxycarboxylic egg, said mineral oi composition being freeof s r. 4

2. An improved mineral oil composition comprising a viscous mineral oilfraction and in admixture therewith'a minor proportion of a reactionproduct obtained by reactin phcsphonis pentachloride with anortho-hydroxybenzoic acid, said mineral oil composition being free ofsulfur.

3. An improved mineral oil. composition comprising a viscous-mineral oilfraction and in ad and .. naawm a. Rom-r H.

BAnimrscnnR. wn-mms HENRY o. rumours.

pentachloride with a compound selected from the

